Extracting prog: 4m33.874421215s
Minimizing prog: 55m56.503636439s
Simplifying prog options: 16m33.187057069s
Extracting C: 5m13.287773249s
Simplifying C: 0s


extracting reproducer from 1 programs
testing a last program of every proc
single: executing 1 programs separately with timeout 6m0s
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-ioctl$NBD_SET_SIZE_BLOCKS-syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_DO_IT
detailed listing:
executing program 0:
r0 = syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x0)
ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0xf)
r1 = syz_open_dev$ndb(&(0x7f00000001c0), 0x0, 0x0)
socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080)={<r2=>0xffffffffffffffff})
ioctl$NBD_SET_SOCK(r1, 0xab00, r2)
ioctl$NBD_DO_IT(r1, 0xab03)

program crashed: INFO: task hung in bdev_release
single: successfully extracted reproducer
found reproducer with 6 syscalls
minimizing guilty program
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-ioctl$NBD_SET_SIZE_BLOCKS-syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK
detailed listing:
executing program 0:
r0 = syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x0)
ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0xf)
r1 = syz_open_dev$ndb(&(0x7f00000001c0), 0x0, 0x0)
socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080)={<r2=>0xffffffffffffffff})
ioctl$NBD_SET_SOCK(r1, 0xab00, r2)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-ioctl$NBD_SET_SIZE_BLOCKS-syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_DO_IT
detailed listing:
executing program 0:
r0 = syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x0)
ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0xf)
r1 = syz_open_dev$ndb(&(0x7f00000001c0), 0x0, 0x0)
socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080))
ioctl$NBD_DO_IT(r1, 0xab03)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-ioctl$NBD_SET_SIZE_BLOCKS-syz_open_dev$ndb-ioctl$NBD_SET_SOCK-ioctl$NBD_DO_IT
detailed listing:
executing program 0:
r0 = syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x0)
ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0xf)
r1 = syz_open_dev$ndb(&(0x7f00000001c0), 0x0, 0x0)
ioctl$NBD_SET_SOCK(r1, 0xab00, 0xffffffffffffffff)
ioctl$NBD_DO_IT(r1, 0xab03)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-ioctl$NBD_SET_SIZE_BLOCKS-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_DO_IT
detailed listing:
executing program 0:
r0 = syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x0)
ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0xf)
socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080)={<r1=>0xffffffffffffffff})
ioctl$NBD_SET_SOCK(0xffffffffffffffff, 0xab00, r1)
ioctl$NBD_DO_IT(0xffffffffffffffff, 0xab03)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_DO_IT
detailed listing:
executing program 0:
syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x0)
r0 = syz_open_dev$ndb(&(0x7f00000001c0), 0x0, 0x0)
socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080)={<r1=>0xffffffffffffffff})
ioctl$NBD_SET_SOCK(r0, 0xab00, r1)
ioctl$NBD_DO_IT(r0, 0xab03)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): ioctl$NBD_SET_SIZE_BLOCKS-syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_DO_IT
detailed listing:
executing program 0:
ioctl$NBD_SET_SIZE_BLOCKS(0xffffffffffffffff, 0xab07, 0xf)
r0 = syz_open_dev$ndb(&(0x7f00000001c0), 0x0, 0x0)
socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080)={<r1=>0xffffffffffffffff})
ioctl$NBD_SET_SOCK(r0, 0xab00, r1)
ioctl$NBD_DO_IT(r0, 0xab03)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-ioctl$NBD_SET_SIZE_BLOCKS-syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_DO_IT
detailed listing:
executing program 0:
r0 = syz_open_dev$ndb(0x0, 0x0, 0x0)
ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0xf)
r1 = syz_open_dev$ndb(&(0x7f00000001c0), 0x0, 0x0)
socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080)={<r2=>0xffffffffffffffff})
ioctl$NBD_SET_SOCK(r1, 0xab00, r2)
ioctl$NBD_DO_IT(r1, 0xab03)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-ioctl$NBD_SET_SIZE_BLOCKS-syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_DO_IT
detailed listing:
executing program 0:
r0 = syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x0)
ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0xf)
r1 = syz_open_dev$ndb(0x0, 0x0, 0x0)
socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080)={<r2=>0xffffffffffffffff})
ioctl$NBD_SET_SOCK(r1, 0xab00, r2)
ioctl$NBD_DO_IT(r1, 0xab03)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-ioctl$NBD_SET_SIZE_BLOCKS-syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_DO_IT
detailed listing:
executing program 0:
r0 = syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x0)
ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0xf)
r1 = syz_open_dev$ndb(&(0x7f00000001c0), 0x0, 0x0)
socketpair$nbd(0x1, 0x1, 0x0, 0x0)
ioctl$NBD_SET_SOCK(r1, 0xab00, 0xffffffffffffffff)
ioctl$NBD_DO_IT(r1, 0xab03)

program did not crash
extracting C reproducer
testing compiled C program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-ioctl$NBD_SET_SIZE_BLOCKS-syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_DO_IT
program crashed: INFO: task hung in read_part_sector
a never seen crash title: INFO: task hung in read_part_sector, ignore
simplifying guilty program options
testing program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-ioctl$NBD_SET_SIZE_BLOCKS-syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_DO_IT
detailed listing:
executing program 0:
r0 = syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x0)
ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0xf)
r1 = syz_open_dev$ndb(&(0x7f00000001c0), 0x0, 0x0)
socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080)={<r2=>0xffffffffffffffff})
ioctl$NBD_SET_SOCK(r1, 0xab00, r2)
ioctl$NBD_DO_IT(r1, 0xab03)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-ioctl$NBD_SET_SIZE_BLOCKS-syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_DO_IT
detailed listing:
executing program 0:
r0 = syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x0)
ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0xf)
r1 = syz_open_dev$ndb(&(0x7f00000001c0), 0x0, 0x0)
socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080)={<r2=>0xffffffffffffffff})
ioctl$NBD_SET_SOCK(r1, 0xab00, r2)
ioctl$NBD_DO_IT(r1, 0xab03)

program crashed: INFO: task hung in bdev_release
extracting C reproducer
testing compiled C program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-ioctl$NBD_SET_SIZE_BLOCKS-syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_DO_IT
program crashed: no output from test machine
a never seen crash title: no output from test machine, ignore
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-ioctl$NBD_SET_SIZE_BLOCKS-syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_DO_IT
detailed listing:
executing program 0:
r0 = syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x0)
ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0xf)
r1 = syz_open_dev$ndb(&(0x7f00000001c0), 0x0, 0x0)
socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080)={<r2=>0xffffffffffffffff})
ioctl$NBD_SET_SOCK(r1, 0xab00, r2)
ioctl$NBD_DO_IT(r1, 0xab03)

program crashed: INFO: task hung in bdev_release
validation run: crashed=true
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-ioctl$NBD_SET_SIZE_BLOCKS-syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_DO_IT
detailed listing:
executing program 0:
r0 = syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x0)
ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0xf)
r1 = syz_open_dev$ndb(&(0x7f00000001c0), 0x0, 0x0)
socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080)={<r2=>0xffffffffffffffff})
ioctl$NBD_SET_SOCK(r1, 0xab00, r2)
ioctl$NBD_DO_IT(r1, 0xab03)

program crashed: INFO: task hung in bdev_release
validation run: crashed=true
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_open_dev$ndb-ioctl$NBD_SET_SIZE_BLOCKS-syz_open_dev$ndb-socketpair$nbd-ioctl$NBD_SET_SOCK-ioctl$NBD_DO_IT
detailed listing:
executing program 0:
r0 = syz_open_dev$ndb(&(0x7f0000000000), 0x0, 0x0)
ioctl$NBD_SET_SIZE_BLOCKS(r0, 0xab07, 0xf)
r1 = syz_open_dev$ndb(&(0x7f00000001c0), 0x0, 0x0)
socketpair$nbd(0x1, 0x1, 0x0, &(0x7f0000000080)={<r2=>0xffffffffffffffff})
ioctl$NBD_SET_SOCK(r1, 0xab00, r2)
ioctl$NBD_DO_IT(r1, 0xab03)

program crashed: INFO: task hung in bdev_release
validation run: crashed=true
reproducing took 1h32m6.04388554s
repro crashed as (corrupted=false):
INFO: task syz.0.17:5888 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.17        state:D stack:27976 pid:5888  tgid:5888  ppid:5783   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5533 [inline]
 __schedule+0x1259/0x6920 kernel/sched/core.c:7284
 __schedule_loop kernel/sched/core.c:7361 [inline]
 schedule+0xdd/0x2c0 kernel/sched/core.c:7376
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7433
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0xccb/0x1bd0 kernel/locking/mutex.c:821
 bdev_release+0x15a/0x6d0 block/bdev.c:1173
 blkdev_release+0x15/0x20 block/fops.c:687
 __fput+0x400/0xb60 fs/file_table.c:512
 task_work_run+0x150/0x240 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:70 [inline]
 exit_to_user_mode_loop+0x1d8/0x700 kernel/entry/common.c:101
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:343 [inline]
 do_syscall_64+0x661/0x790 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc4e199e2d9
RSP: 002b:00007fff08010c28 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007fc4e1c27da0 RCX: 00007fc4e199e2d9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007fc4e1c27da0 R08: 0000000000000006 R09: 0000000000000000
R10: 00007fc4e1c27cb0 R11: 0000000000000246 R12: 0000000000040609
R13: 00007fc4e1c25fac R14: 00000000000402fd R15: 00007fff08010d30
 </TASK>
INFO: task syz.0.17:5889 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.17        state:D stack:28024 pid:5889  tgid:5888  ppid:5783   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5533 [inline]
 __schedule+0x1259/0x6920 kernel/sched/core.c:7284
 __schedule_loop kernel/sched/core.c:7361 [inline]
 schedule+0xdd/0x2c0 kernel/sched/core.c:7376
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7433
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0xccb/0x1bd0 kernel/locking/mutex.c:821
 bdev_release+0x15a/0x6d0 block/bdev.c:1173
 blkdev_release+0x15/0x20 block/fops.c:687
 __fput+0x400/0xb60 fs/file_table.c:512
 task_work_run+0x150/0x240 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:70 [inline]
 exit_to_user_mode_loop+0x1d8/0x700 kernel/entry/common.c:101
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:343 [inline]
 do_syscall_64+0x661/0x790 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc4e199e2d9
RSP: 002b:00007fc4e2914028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: 0000000000000000 RBX: 00007fc4e1c25fa0 RCX: 00007fc4e199e2d9
RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000004
RBP: 00007fc4e1a35888 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc4e1c26038 R14: 00007fc4e1c25fa0 R15: 00007fff08010ac8
 </TASK>

Showing all locks held in the system:
locks held by khungtaskd/31: 1, last CPU#0:
 #0: ffffffff8fdec5e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffffffff8fdec5e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8fdec5e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6871
locks held by getty/5358: 2, on CPU#0:
 #0: ffff888024ffb0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc900032432e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14e0 drivers/tty/n_tty.c:2211
locks held by udevd/5666: 1, on CPU#0:
 #0: ffff888029ff3350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:990
locks held by udevd/5767: 1, on CPU#1:
 #0: ffff888029ff7350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:990
locks held by syz.0.17/5888: 1, on CPU#0:
 #0: ffff888029ff3350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1173
locks held by syz.0.17/5889: 1, on CPU#1:
 #0: ffff888029ff3350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1173
locks held by udevd/5917: 1, on CPU#1:
 #0: ffff88802a103350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:990
locks held by kworker/1:5/5947: 3, on CPU#1:
 #0: ffff88801d05b140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371
 #1: ffffc900035f7d08 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372
 #2: ffff88803450a250 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x1b8/0x6330 drivers/net/netdevsim/fib.c:1490
locks held by syz.1.18/5948: 1, on CPU#0:
 #0: ffff888029ff7350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1173
locks held by syz.1.18/5949: 1, on CPU#0:
 #0: ffff888029ff7350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1173
locks held by udevd/5955: 1, on CPU#1:
 #0: ffff88802a107350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:990
locks held by syz.2.19/5985: 1, on CPU#1:
 #0: ffff88802a103350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1173
locks held by syz.2.19/5986: 1, on CPU#1:
 #0: ffff88802a103350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1173
locks held by syz.3.20/6027: 1, on CPU#1:
 #0: ffff88802a107350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1173
locks held by syz.3.20/6028: 1, on CPU#1:
 #0: ffff88802a107350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1173
locks held by udevd/6033: 1, on CPU#1:
 #0: ffff88802a1cb350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:990
locks held by udevd/6035: 1, on CPU#1:
 #0: ffff88802a233350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:990
locks held by syz.4.21/6072: 1, on CPU#1:
 #0: ffff88802a1cb350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1173
locks held by syz.4.21/6073: 1, on CPU#1:
 #0: ffff88802a1cb350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1173
locks held by udevd/6078: 1, on CPU#0:
 #0: ffff88802a1cf350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:990
locks held by syz.5.22/6115: 1, on CPU#1:
 #0: ffff88802a1cf350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1173
locks held by syz.5.22/6116: 1, on CPU#1:
 #0: ffff88802a1cf350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1173
locks held by syz.6.23/6160: 1, on CPU#0:
 #0: ffff88802a233350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1173
locks held by syz.6.23/6161: 1, on CPU#0:
 #0: ffff88802a233350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1173
locks held by udevd/6169: 1, on CPU#0:
 #0: ffff88802a30b350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:990
locks held by udevd/6171: 1, on CPU#1:
 #0: ffff88802a237350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:990
locks held by syz.7.24/6208: 1, on CPU#1:
 #0: ffff88802a237350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1173
locks held by syz.7.24/6209: 1, on CPU#1:
 #0: ffff88802a237350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1173
locks held by syz.8.25/6250: 1, on CPU#1:
 #0: ffff88802a30b350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1173
locks held by syz.8.25/6251: 1, on CPU#1:
 #0: ffff88802a30b350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1173
locks held by udevd/6252: 1, on CPU#1:
 #0: ffff88802a30f350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:990
locks held by syz.9.26/6294: 1, on CPU#1:
 #0: ffff88802a30f350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1173
locks held by syz.9.26/6295: 1, on CPU#1:
 #0: ffff88802a30f350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1173

=============================================

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:123
 nmi_trigger_cpumask_backtrace+0x21f/0x2a0 lib/nmi_backtrace.c:66
 trigger_all_cpu_backtrace include/linux/nmi.h:164 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x141/0x190 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
 watchdog+0xcb1/0x1030 kernel/hung_task.c:561
 kthread+0x373/0x450 kernel/kthread.c:436
 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64
Code: 97 96 02 e9 53 50 03 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 53 38 17 00 fb f4 <c3> cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc900001a7e00 EFLAGS: 00000246
RAX: 00000000001519a9 RBX: ffff888020684b00 RCX: ffffffff8bd48235
RDX: 0000000000000001 RSI: ffffffff8e3e346f RDI: ffffffff8c625580
RBP: ffffed10040d0960 R08: 0000000000000001 R09: ffffed10170667bd
R10: ffff8880b8333deb R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000000 R14: 1ffff92000034fc4 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff888122a46000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6e79f87900 CR3: 0000000029f98000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline]
 default_idle+0x9/0x10 arch/x86/kernel/process.c:768
 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:199 [inline]
 do_idle+0x3ae/0x5b0 kernel/sched/idle.c:355
 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:454
 start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312
 common_startup_64+0x13e/0x158
 </TASK>

final repro crashed as (corrupted=false):
INFO: task syz.0.17:5888 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.17        state:D stack:27976 pid:5888  tgid:5888  ppid:5783   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5533 [inline]
 __schedule+0x1259/0x6920 kernel/sched/core.c:7284
 __schedule_loop kernel/sched/core.c:7361 [inline]
 schedule+0xdd/0x2c0 kernel/sched/core.c:7376
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7433
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0xccb/0x1bd0 kernel/locking/mutex.c:821
 bdev_release+0x15a/0x6d0 block/bdev.c:1173
 blkdev_release+0x15/0x20 block/fops.c:687
 __fput+0x400/0xb60 fs/file_table.c:512
 task_work_run+0x150/0x240 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:70 [inline]
 exit_to_user_mode_loop+0x1d8/0x700 kernel/entry/common.c:101
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:343 [inline]
 do_syscall_64+0x661/0x790 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc4e199e2d9
RSP: 002b:00007fff08010c28 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007fc4e1c27da0 RCX: 00007fc4e199e2d9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007fc4e1c27da0 R08: 0000000000000006 R09: 0000000000000000
R10: 00007fc4e1c27cb0 R11: 0000000000000246 R12: 0000000000040609
R13: 00007fc4e1c25fac R14: 00000000000402fd R15: 00007fff08010d30
 </TASK>
INFO: task syz.0.17:5889 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.17        state:D stack:28024 pid:5889  tgid:5888  ppid:5783   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5533 [inline]
 __schedule+0x1259/0x6920 kernel/sched/core.c:7284
 __schedule_loop kernel/sched/core.c:7361 [inline]
 schedule+0xdd/0x2c0 kernel/sched/core.c:7376
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7433
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0xccb/0x1bd0 kernel/locking/mutex.c:821
 bdev_release+0x15a/0x6d0 block/bdev.c:1173
 blkdev_release+0x15/0x20 block/fops.c:687
 __fput+0x400/0xb60 fs/file_table.c:512
 task_work_run+0x150/0x240 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:70 [inline]
 exit_to_user_mode_loop+0x1d8/0x700 kernel/entry/common.c:101
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:343 [inline]
 do_syscall_64+0x661/0x790 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc4e199e2d9
RSP: 002b:00007fc4e2914028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: 0000000000000000 RBX: 00007fc4e1c25fa0 RCX: 00007fc4e199e2d9
RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000004
RBP: 00007fc4e1a35888 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc4e1c26038 R14: 00007fc4e1c25fa0 R15: 00007fff08010ac8
 </TASK>

Showing all locks held in the system:
locks held by khungtaskd/31: 1, last CPU#0:
 #0: ffffffff8fdec5e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffffffff8fdec5e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8fdec5e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6871
locks held by getty/5358: 2, on CPU#0:
 #0: ffff888024ffb0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc900032432e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14e0 drivers/tty/n_tty.c:2211
locks held by udevd/5666: 1, on CPU#0:
 #0: ffff888029ff3350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:990
locks held by udevd/5767: 1, on CPU#1:
 #0: ffff888029ff7350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:990
locks held by syz.0.17/5888: 1, on CPU#0:
 #0: ffff888029ff3350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1173
locks held by syz.0.17/5889: 1, on CPU#1:
 #0: ffff888029ff3350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1173
locks held by udevd/5917: 1, on CPU#1:
 #0: ffff88802a103350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:990
locks held by kworker/1:5/5947: 3, on CPU#1:
 #0: ffff88801d05b140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371
 #1: ffffc900035f7d08 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372
 #2: ffff88803450a250 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x1b8/0x6330 drivers/net/netdevsim/fib.c:1490
locks held by syz.1.18/5948: 1, on CPU#0:
 #0: ffff888029ff7350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1173
locks held by syz.1.18/5949: 1, on CPU#0:
 #0: ffff888029ff7350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1173
locks held by udevd/5955: 1, on CPU#1:
 #0: ffff88802a107350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:990
locks held by syz.2.19/5985: 1, on CPU#1:
 #0: ffff88802a103350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1173
locks held by syz.2.19/5986: 1, on CPU#1:
 #0: ffff88802a103350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1173
locks held by syz.3.20/6027: 1, on CPU#1:
 #0: ffff88802a107350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1173
locks held by syz.3.20/6028: 1, on CPU#1:
 #0: ffff88802a107350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1173
locks held by udevd/6033: 1, on CPU#1:
 #0: ffff88802a1cb350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:990
locks held by udevd/6035: 1, on CPU#1:
 #0: ffff88802a233350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:990
locks held by syz.4.21/6072: 1, on CPU#1:
 #0: ffff88802a1cb350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1173
locks held by syz.4.21/6073: 1, on CPU#1:
 #0: ffff88802a1cb350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1173
locks held by udevd/6078: 1, on CPU#0:
 #0: ffff88802a1cf350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:990
locks held by syz.5.22/6115: 1, on CPU#1:
 #0: ffff88802a1cf350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1173
locks held by syz.5.22/6116: 1, on CPU#1:
 #0: ffff88802a1cf350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1173
locks held by syz.6.23/6160: 1, on CPU#0:
 #0: ffff88802a233350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1173
locks held by syz.6.23/6161: 1, on CPU#0:
 #0: ffff88802a233350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1173
locks held by udevd/6169: 1, on CPU#0:
 #0: ffff88802a30b350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:990
locks held by udevd/6171: 1, on CPU#1:
 #0: ffff88802a237350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:990
locks held by syz.7.24/6208: 1, on CPU#1:
 #0: ffff88802a237350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1173
locks held by syz.7.24/6209: 1, on CPU#1:
 #0: ffff88802a237350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1173
locks held by syz.8.25/6250: 1, on CPU#1:
 #0: ffff88802a30b350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1173
locks held by syz.8.25/6251: 1, on CPU#1:
 #0: ffff88802a30b350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1173
locks held by udevd/6252: 1, on CPU#1:
 #0: ffff88802a30f350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:990
locks held by syz.9.26/6294: 1, on CPU#1:
 #0: ffff88802a30f350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1173
locks held by syz.9.26/6295: 1, on CPU#1:
 #0: ffff88802a30f350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1173

=============================================

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:123
 nmi_trigger_cpumask_backtrace+0x21f/0x2a0 lib/nmi_backtrace.c:66
 trigger_all_cpu_backtrace include/linux/nmi.h:164 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x141/0x190 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
 watchdog+0xcb1/0x1030 kernel/hung_task.c:561
 kthread+0x373/0x450 kernel/kthread.c:436
 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64
Code: 97 96 02 e9 53 50 03 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 53 38 17 00 fb f4 <c3> cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc900001a7e00 EFLAGS: 00000246
RAX: 00000000001519a9 RBX: ffff888020684b00 RCX: ffffffff8bd48235
RDX: 0000000000000001 RSI: ffffffff8e3e346f RDI: ffffffff8c625580
RBP: ffffed10040d0960 R08: 0000000000000001 R09: ffffed10170667bd
R10: ffff8880b8333deb R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000000 R14: 1ffff92000034fc4 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff888122a46000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6e79f87900 CR3: 0000000029f98000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline]
 default_idle+0x9/0x10 arch/x86/kernel/process.c:768
 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:199 [inline]
 do_idle+0x3ae/0x5b0 kernel/sched/idle.c:355
 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:454
 start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312
 common_startup_64+0x13e/0x158
 </TASK>